Relugolix and Voxilaprevir: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Relugolix
Voxilaprevir
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Here's what's going on. Relugolix (Orgovyx) is moved out of your body with the help of a transporter called P-gp. Voxilaprevir can slow that transporter down. When it does, more relugolix stays in your system than usual, which can raise your chance of side effects.
The good news is this is very manageable. Your care team can space the two medicines apart, watch you a little more closely, or adjust your plan so both drugs do their job safely. Please don't stop or change either medicine on your own. Just check in with your pharmacist or doctor so they can guide you.
Mechanism: Voxilaprevir inhibits P-gp-mediated efflux of relugolix (a P-gp substrate), increasing relugolix exposure and adverse-reaction risk. Direction: increased relugolix effect. Neither drug's action depends on prodrug activation here.
- Magnitude: Not established for voxilaprevir specifically; a study with erythromycin (P-gp inhibitor) raised relugolix AUC 3.5-fold and Cmax 2.9-fold.
- Evidence: Probable. Onset unspecified.
- Management: Avoid concurrent use if possible. If unavoidable, give relugolix first, separate by at least 6 hours, and monitor more frequently for adverse reactions. Relugolix may be interrupted up to 2 weeks for short P-gp inhibitor courses; if held >7 days, restart with 360 mg loading dose then 120 mg daily.
What happens
Increased relugolix exposure
Interaction Deep Dive
The combined use of relugolix (a P-gp substrate) with P-gp inhibitors should be avoided, since doing so can raise relugolix exposure and thereby heighten the likelihood of adverse reactions linked to relugolix. When coadministration cannot be avoided, give relugolix or relugolix/estradiol/norethindrone acetate first, allow a gap of at least 6 hours between doses, and increase the frequency of monitoring for adverse reactions12. Relugolix therapy may be paused for as long as 2 weeks to accommodate a brief course of treatment with certain P-gp inhibitors, then resumed once the P-gp inhibitor has been stopped. Should relugolix be interrupted for more than 7 days, it should be reintroduced using a loading dose of 360 mg on day one, followed by 120 mg once daily thereafter. In a drug interaction study, giving relugolix (P-gp substrate) together with erythromycin (P-gp inhibitor) raised the AUC and Cmax of relugolix by 3.5-fold and 2.9-fold, respectively1.
Why it happens (mechanism)
Inhibition of P-gp-mediated efflux transport of relugolix
How to manage this interaction
What your care team may do:
- Try to avoid using these two together when there is another option.
- If both are needed, take relugolix first and separate the doses by at least 6 hours.
- Watch you more closely for relugolix side effects.
- For a short course of the interacting drug, they may pause relugolix and restart it afterward (with a loading dose if it was held more than 7 days).
What you should do: Keep taking both exactly as prescribed for now, and ask your pharmacist or prescriber how they want to handle the timing. Report any new or worsening symptoms promptly.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In a drug interaction study, giving relugolix (a P-gp substrate) together with erythromycin (a P-gp inhibitor) raised the AUC of relugolix by 3.5-fold and its Cmax by 2.9-fold 1.
Common questions
Can I take Relugolix and Voxilaprevir together?
Voxilaprevir can raise relugolix levels and side-effect risk by blocking P-gp, so avoid combining them when possible; if both are needed, your team may separate doses by at least 6 hours and monitor you more closely. Don't change either medicine on your own. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Voxilaprevir interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Relugolix and Voxilaprevir interaction managed?
What your care team may do: Try to avoid using these two together when there is another option. If both are needed, take relugolix first and separate the doses by at least 6 hours. Watch you more closely for relugolix side effects. For a short course of the interacting drug, they may pause relugolix and restart it afterward (with a loading dose if it was held more than 7 days). What you should do:… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Relugolix or Voxilaprevir need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: ORGOVYX oral tablets, relugolix oral tablets. Sumitomo Pharma America, Inc (per FDA), Marlborough, MA, 2025. DailyMed
- Product Information: MYFEMBREE(R) oral tablets, relugolix, estradiol, norethindrone acetate oral tablets. Myovant Sciences Inc (per FDA), Brisbane, CA, 2021. DailyMed
Keep reading about Relugolix
Keep reading about Voxilaprevir
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